Improvement in air-pipes for furnaces



J. P. DAWSON.

Improvement in Air-Pipes for Furnaces.

Patented July 9,1872.

lease-1 ISTNITED STATES JOHN P. DAWSON, OF DES MOINES, IOWA.

IMPROVEMENT IN AIR-PIPES FOR FURNACES.

Specification forming part of Letters Patent No. 128,864, dated July 9,1872.

SPECIFICATION.

Specification describing a certain Improved Attachment for Furnaces,invented by JOHN P. DAWSON, of Des Moines, in the county of Polk andState of Iowa.

My invention is an improved means of conducting and distributing acurrent ofair to a furnace-fire for the purpose of aiding combustion andkeeping the grate-bars cool. It consists in combining two cylinders, onewithin the other, in such a manner that one of them may be turned toregulate the distribution of air when they are placed under afurnacegrate bar, as hereinafter fully set forth.

Figure l of my drawing is a vertical central section of my doublecylinder, and illustrates the manner of its construction and operationas attached under a furnace-grate.

A Arepresents a common grate-bar. B is a common bar or support. C Ois ahollow cylinder, made of metal, six inches in diameter; the size mayvary, as desired. One of the ends may be permanently closed or coveredwith a movable cap 5 the other end is open, and formed to connect with acommon conducting-pipe. D D is a metal cylinder tted inside of thecylinder C O in such a manner that it can be turned. a a are wide slotsrunning lengthwise in the two cylinders. The slots may vary in size andshape, but must be uniform in the two cylinders. b b are smaller slotsor perforations. c is a slot in the under part of the outside cylinder.d is a handle, secured in a common way to the inner cylinder D D, andpasses through and traverses the slot c when the inner cylinder isturned. The inner cylinder may be stationary, and the outside one madeto turn and accomplish the objects contemplated in my invention. frepresents a shaft that may pass longitudinally through the innercylinder and serve to keep the two cylinders in their proper relativepositions, and also as an axis, upon which `turns one of them; but thecylinders can be mounted and attached in a common way, and operatedwithout the shaft f.

Fig. 2 is a miniature perspective view, illustratin g the manner ofapplying and operating my double cylinder attached to va furnace.

flhe same letters of reference are used as in .and distribution of theair.

designate a common conducting-pipe, which is designed to connect with afan.

To operate my invention it must be adjusted to suit the variousconditions of the furnacelire. Fig. 1 represents .the large slots a ahalt closed, and the smaller openings b b entirely closed. In thiscondition a moderate blast will be blown upon the front part of thegrate and fire, and the handle d will be in the center of the transverseslot o. To lessen the blast and close the slots a a entirely the handled will be turned backward to the rear end of the slot c. To increase theblast and to open the slots a and b entirely, bring the handle d to thefront end of the slot c. Moving the handle backward and forward turnsthe inner cylinder and opens and closes the slots or-apertures a and b,which can vary in size, form, and number, as desired. Y

I am aware that conducting and distributing pipes have been placed undergrate-bars in a manner similar to my attachment for the same purposes,and that longitudinal sliding registers have been used to regulate theescape The object sought thereby is to govern the quantity, force, anddirection of the air. In some conditions of the fire the blast must beconcentrated upon the front part of the fire; in other stages the blastshould be distributed over considerable to such a degree as may bedesired to regulate the quantity and direction of the blast. By areverse motion I can open the passage a partly, so that the air willescape in a continuous line from the top of the cylinder only7 anddirectly upward to the front of the grate and lire. As the condition ofthe fire demands, the passages a b may be opened further or entirely, sothat a larger volume of air will escape from a lower point in thecylinder, and in an angling and scribed, as a means to distribute air toa furrearward direction, to strike a larger surface nace to keep thegrate-bars cool and to reguof grate-bar, fuel, and fire. late the fire.

. Claim JOHN P. DAWSON.

I claim as my invention- Witnesses:

The double cylinder C C and D D with openings a and b and handle d,substantially as de- LoUIs RUTTKAY, WM. W. WITMER.

